With visual electrophysiology you can:
- Detect and monitor macular degeneration with longitudinal studies
- Screen for retinal toxicity from Plaquenil and other medications
- Assess damage from diabetic retinopathy
- Diagnose genetic vision conditions
Retinal mapping with multifocal electroretinography (mfERG)
Multifocal ERG is a visual electrophysiology test that produces a detailed map of retinal function. This test is widely used to objectively detect localized damage and subtle functional abnormalities of the macula and surrounding areas. Learn more about mfERG.
You can perform multifocal ERGs using the LI-LCD stimulator with any of the Diagnosys clinical systems.
CPT code for mfERG: 922274

Detect and monitor macular degeneration
Macular degeneration changes can be seen on mfERG before they show up as structural damage on optical coherence tomography (OCT). This early detection enables earlier interventions before significant vision loss occurs. Comparing mfERG from visit to visit can objectively map treatment efficacy of preservation of vision.
Screen for retinal toxicity
Visual electrophysiology can be used to screen for retinal toxicity. Medications like Hydroxychloroquine (Plaquenil), Chloroquine, Tamoxifen, and Vigabatrin can cause damage when they accumulate in the eye. A specialty mfERG can be used as a routine objective screening for detecting functional changes in the retina due to long-term medication use.

Full-field ERG measures changes across global retinal function
A full-field ERG utilizes the dark and light adapted stages of the retina to objectively assess cone and rod specific function. This test also evaluates inner retinal function, namely amacrine and bipolar cell function; while specialized ERGs such as the PERG and PhNR evaluate retinal ganglion cell function.
You can perform full-field ERGs using Diagnosys ColorDome and ColorFlash stimulators along with any of our clinical systems.
CPT Code for full-field ERG: 92273
Diagnose genetic conditions
Several genetic retinal conditions present characteristic visual electrophysiological patterns. ERG can detect these functional abnormalities objectively by measuring the amplitudes of responses from several layers of the retina.
